Oscillating engine



(No Model.)

L. GRISCQM.

OSGILLATING ENGINE. f No. 253,038. Patented Jafn. 31.1882.

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UNTTEED STaTas PATENT @Trina LEWIS GRISOOM, OF POTTSVILLE, PENNSYLVANIA.

OSCILLATING ENGINE.

SPECIFICATION forming part of-Letters Patent No. 253,038, dated January 31, 1882.

Application tiled November 21, 1881. (No model.)

To all whom it may concern:

Be it known that I, LEWIS GRISGOM, a citizen of theUnited States, residinginPottsville, Schuylkill county, Pennsylvania, have invented an Improvement in Oscillating Engines, of which the following` is a specification.

The object ot' my invention is to increase thel port area of an oscillating engine without a corresponding increase in the extent ot` oscillation of the cylinder; and this object I attain in the manner which I will now proceed to describe, reference being had to the accompanying drawings, in which- Figure lis a perspective view ofthe cylinder and standards of an oscillating engine, one of the standards being detached and reversed in order to show the ports; Fig. 2, a face viewof the cylinder-trannion and its port; Fig. 3, a face view of the ports in the standard, and Figs. 4 and 5 diagrams illustrating the relation of the ports to each other as the cylinder oscillates. l

A is the cylinder of the engine, and B B the opposite vertical standards, between which the cylinder is hung and oscillates, said cylinder having trunnions a, with central journals, b. These journals are adapted to bearings 1,formed yin the upper ends of the standards B, and in circular bosses c on the latter, suitable means. being provided for maintaining the faces of the trunnions c and bosses e in steam-tight contact with each other.

In an oscillating engine having a single port only in each end oi' the cylinder the area of port-openingis necessarilylimited bythe extent ot'oscillation of the cylinder, and in short-stroke engines the ports areA unduly contracted.

The object ot' my invention is to overcome this dificulty 5 and in carrying out my invention I adopt the arrangement of ports which I will now proceed to describe.

In either 'or both of the cylinder-trunnions a are formed two sets of ports,j'j"f2 and i t" i2, the ports ff f2 communicating with the front end of the cylinder, and the ports i, i and i2 communicating with the rear end of the same.

A Either or both of the standards B are divided at the upper endbya partition (shown bydot ted lines in Fig. 3) into a steam-chamber, D, and an exhaust-chamber, E, the boss e having ports m m' and a a communicating with the steam-chamber D, and ports or 0c and y ycommunicating with the exhaust-chamber E. The ports m m and m x are so located as to work in connection with the portsj',f,and f2 of the cylinder, and the ports nu and y y are adapted to worl; in connection with the ports g, g', and g2 ot' the cylinder in the following manner: When the trunnion a of the cylinder occupies the position shown in Figli the ports ff coincide with the ports mm', and the port]E2 occupies a position between the portsxx,tlie ports i t2 coinciding with the ports y y' and the port fi occupying a position between the ports u a. Steam from the chamber D thus enters the front end ot the cylinder through the ports j' f and m m', and is exhausted from the opposite end of the cylinder through the ports a" i2 and y y and chamber E, the ports t' and f 2 being blind ports--thatl is to say, serving neither as steam nor exhaust ports. When the cylinder is in this position the piston is at halfstroke and is moving rearward, and as said cylinder oscillates on its trunnionbearin gs the relation of the ports in the cylinder to those in the standard B changes until, when the piston has reached mid-stroke in a forward direction, the ports occupy the relations shown in Fig. 5, steam entering the rear end of the cylinder through the ports yi t" and a n', and being. exhausted from vthe front end of the cylinder through the ports :v x and f f2, the ports i2 andf working blind between the ports y y' and m m', respectively.

It will be seen that the center port,vz" onf', of the cylinder is always an acting port, and is re-enforced by one of the other ports otl the set both in supplying steam to and exhausting it from the cylinder, the remaining port of the set working blind.

The rule to be observed in laying out the ports is that the distance between the ports m and x and a and 'y shall be less bya little more than the width of a port than the distance between the ports of a cylinder, or between the ports m and m/,a and a', x and x', or y andy', so that while the center ports of the cylinder are caused by the movement of said cylinder to coincide alternately with the steam and exhaust ports, the upper and lower ports of the set alternately act as blind ports. The same principle may be applied to engineshavingmore IOO than three cylinder-ports inveaeh set. For instance, the cylinder may have tive ports in a set, and the standard may have three steam and three exhaust ports in each set, instead of two, as in the drawings, there being in this case two blind ports in each set of cylinderports, and by the same rule the number oi' ports may be increased as desired.

I have described myinvention as applied to a steam-engine; but it may be applied to air or gas engines as Well, the invention heilig, as

above set forth, especiallyadvantageousin engines of short stroke, where the oscillating movement is of limited extent and the ports are necessarily contracted in Width.

I claim asmy invention- The combination of the standard B of the engine, having two sets of steam and exhaust ports spaced as described with the cylinder having two sets of ports spaced in respect to those of the standard as set fort-h, whereby the ports above and below the center port serve alternately as blind ports and acting ports, as set forth.

In testimony whereof I have signed my name to this specification in thepreseneeof tw'o subseribing,` witnesses.

LEWIS GRISCOM.

Witnesses: f

1t. H. SMITH, LEsLiE GRIsooM. 

